Carbon in iron phases under high pressure
2005 (English)In: Geophysical Research Letters, Vol. 32Article in journal (Refereed) Published
The influence of carbon impurities on the properties of iron phases (bcc, hcp, dhcp, fcc) has been studied using the first-principles projector augmented-wave (PAW) method for a wide pressure range. It is shown that the presence of ~6 at. % of interstitial carbon has a little effect on the calculated structural sequence of the iron phases under high pressure. The bcc → hcp transition both for pure iron and iron containing carbon takes place around 9 GPa. According to the enthalpies comparison, the solubility of carbon into the iron solid is decreased by high pressure. The coexistence of iron carbide (Fe3C) + pure hcp Fe is most stable phase at high pressure compared with other phases. Based on the analysis of the pressure-density dependences for Fe3C and hcp Fe, we suggest that there might be some fraction of iron carbide present in the core.
Place, publisher, year, edition, pages
2005. Vol. 32
IdentifiersURN: urn:nbn:se:uu:diva-76328DOI: doi:10.1029/2005GL024187, 2005OAI: oai:DiVA.org:uu-76328DiVA: diva2:104240